Gardening Articles: Edibles :: Vegetables

Corn Confidential

by National Gardening Association Editors

You watered it, fed it, and nursed your corn crop through the summer. Finally it's time. You pick a few ears and run for the pot of water boiling on the stove. But as you eagerly husk the ears you find them smiling up at you like a hockey player who's played too many games without a mouthguard. If you're really unlucky you find you've got more cob than kernel.

It doesn't seem like too much to ask: one stalk, one perfect ear of corn. Yet many gardeners have trouble making that yield. Corn really isn't made for the home garden. It takes a lot of space, and has a particular style of pollination that causes problems.

If a tomato blossom doesn't get pollinated it won't make a fruit, but others will come along quickly enough. Chances are you'll never even notice that anything is amiss. But for corn, incomplete pollination is obvious. It produces gap-toothed ears and gives a subtle cobby flavor to the corn that isn't quite right.

Corn pollination is a complex process. The pollen forms on the tassel and has to get from there to the female flowers deep within the husk of the emerging ears. The silk is the road it travels. Each silk is connected to a pair of female flowers on the cob. When a female flower is fertilized it forms a seed--a kernel of corn. If a flower is not fertilized it leaves a gap on the cob. That means that hundreds of (maybe even a thousand) fertilizations have to take place to fill out a single ear of corn.

In farm plantings there's so much pollen in the air and so many fields of corn in the vicinity that pollination is inevitable. Even in the smallest corn patch there's plenty of pollen to go around. Each tassel produces millions of microscopic grains of it. The problem, especially in a small garden, is getting it where it belongs. Wind will whisk it away. Rain will hurl it to the ground. Heat will kill it. In temperatures over 90oF pollen grains remain viable for less than 24 hours.

Home garden corn patches suffer from the "edge effect." A long and narrow patch will have lots of plants on the edge, making it more likely that their pollen will blow away. The longer the edge of the patch, the lower the percent of pollination. By planting in blocks instead of long rows, and facing the shortest edge in the direction of the prevailing winds, you increase the likelihood of pollination even more.